/**
 * Copyright (c) 2007-2014 The LIBLINEAR Project. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
 * and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. Neither name of copyright holders nor the names of its contributors may be used to endorse or
 * promote products derived from this software without specific prior written permission.
 *
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package de.bwaldvogel.liblinear;

public class FeatureNode implements Feature {

	public final int index;
	public double value;

	public FeatureNode(final int index, final double value) {
		if (index < 0) {
			throw new IllegalArgumentException("index must be >= 0");
		}
		this.index = index;
		this.value = value;
	}

	/**
	 * @since 1.9
	 */
	@Override
	public int getIndex() {
		return index;
	}

	/**
	 * @since 1.9
	 */
	@Override
	public double getValue() {
		return value;
	}

	/**
	 * @since 1.9
	 */
	@Override
	public void setValue(double value) {
		this.value = value;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + index;
		long temp;
		temp = Double.doubleToLongBits(value);
		result = prime * result + (int) (temp ^ temp >>> 32);
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj == null) {
			return false;
		}
		if (getClass() != obj.getClass()) {
			return false;
		}
		FeatureNode other = (FeatureNode) obj;
		if (index != other.index) {
			return false;
		}
		if (Double.doubleToLongBits(value) != Double.doubleToLongBits(other.value)) {
			return false;
		}
		return true;
	}

	@Override
	public String toString() {
		return "FeatureNode(idx=" + index + ", value=" + value + ")";
	}
}
